How to strafe the screen view

I would like to see my object by moving my view side by side, it is caleld strafe in video game.

In the 3D window? Shift-middle mouse button.

I will post all my questions here.
How to select multiple vertices?

Shift + right mouse button.

Or press B to box select.

Still trying to slect 2 vertices on a circle. Watching this video I notice that

  1. my cube have a purple around it.
  2. Not all the surrounding of the starting cube is in purple but not every sides as opposed in the video he got them all yellow.

Found it I need to be in edit more.

How can I rotate the view? Ex: I want to have it straith.